Mix the strongest soap-lees with quicklime to the consistency of milk; let it lie on the stone, etc., for twenty-four hours; then clean it off, and wash with soap and water, and it will appear as new. The polish will require to be renewed by the process given above.
Mix with a quarter pint of soap-lees half a gill of turpentine, sufficient pipeclay and bullock's gall to make the whole into a rather thick paste. Apply it to the marble with a soft brush; and after a day or two, when quite dry, rub it off with a soft rag. Apply this a second or third time till the marble is quite clean.